Method for cleaning lanthanum gallium silicate wafer

Abstract

The present disclosure provides a method for cleaning a lanthanum gallium silicate wafer which comprises the following steps: at a step of 1, a cleaning solution constituted of phosphorous acid, hydrogen peroxide and deionized water is utilized to clean the lanthanum gallium silicate wafer with a megahertz sound wave; at a step of 2, the cleaned lanthanum gallium silicate wafer is rinsed and dried by spinning; at a step of 3, a cleaning solution constituted of ammonia, hydrogen peroxide and deionized water is utilized to clean the lanthanum gallium silicate wafer with the megahertz sound wave; at a step of 4, the cleaned lanthanum gallium silicate wafer is rinsed and dried by spinning; and at a step of 5, the rinsed and dried wafer is placed in an oven to be baked. The present invention shortens a period of acidic cleaning process and prolongs a period of alkaline cleaning and utilizes a more effective cleaning with megahertz sound wave to replace the conventional ultrasonic cleaning to solve the issue of cleaning the lanthanum gallium silicate wafer after a cutting process and to improve surface cleanliness of the lanthanum gallium silicate wafer to get a better cleaning effect.

The invention claimed is: 
     
       1. A method for cleaning a lanthanum gallium silicate wafer comprising:
 at a step of 1, utilizing an acidic cleaning solution comprising phosphoric acid, hydrogen peroxide and deionized water to clean the lanthanum gallium silicate wafer with a megahertz sound wave; 
 at a step of 2, rinsing and drying the cleaned lanthanum gallium silicate wafer by spinning; 
 at a step of 3, utilizing an alkaline cleaning solution comprising ammonia, hydrogen peroxide and deionized water to clean the lanthanum gallium silicate wafer with the megahertz sound wave; 
 at a step of 4, rinsing and drying the cleaned lanthanum gallium silicate wafer by spinning; and 
 at a step of 5, baking the rinsed and dried wafer in an oven, 
 wherein a time period for alkaline cleaning is longer than that for acidic cleaning, and wherein the method uses only phosphoric acid without using any other acid. 
 
     
     
       2. The method for cleaning a lanthanum gallium silicate wafer according to  claim 1 , wherein at the step of 1, the cleaning solution constituted of phosphoric acid, hydrogen peroxide and deionized water has a mass ratio of H 3 PO 4 :H 2 O 2 :H 2 O of 1:1:50˜100. 
     
     
       3. The method for cleaning a lanthanum gallium silicate wafer according to  claim 1 , wherein at the step of 1, the cleaning with the megahertz sound wave is implemented at a temperature of 50˜60° C. for 10 minutes. 
     
     
       4. The method for cleaning a lanthanum gallium silicate wafer according to  claim 1 , wherein at the step of 2, the lanthanum gallium silicate wafer is rinsed by deionized water at a room temperature for 10 minutes. 
     
     
       5. The method for cleaning a lanthanum gallium silicate wafer according to  claim 1 , wherein at the step of 3, the cleaning solution constituted of ammonia, hydrogen peroxide and deionized water has a mass ratio of NH 3 :H 2 O 2 :H 2 O of 1:2:50-100. 
     
     
       6. The method for cleaning a lanthanum gallium silicate wafer according to  claim 1 , wherein at the step of 3, the cleaning with the megahertz sound wave is implemented at a temperature of 50-60° C. for 50 minutes. 
     
     
       7. The method for cleaning a lanthanum gallium silicate wafer according to  claim 1 , wherein at the step of 4, the lanthanum gallium silicate wafer is rinsed by deionized water at a room temperature for 10 minutes. 
     
     
       8. The method for cleaning a lanthanum gallium silicate wafer according to  claim 1 , wherein at the step of 5, the lanthanum gallium silicate wafer is baked in a drying oven at a temperature of 40-90° C. for 20-30 minutes.